1.1
The
Institution of Public Lighting Engineers (IPLE) is pleased to learn of
the
Select Committee's inquiry into road safety and welcomes the
opportunity to
submit evidence in support of measures to improve safety to
all road users
during the hours of darkness.

1.2
The
IPLE was formerly the Association of Public Lighting Engineers,
founded in
1924. IPLE is affiliated to the Council of Engineering
Institutions and is the
sole professional body representing those
engineers engaged in the provision of
public lighting in the external
environment.

The
membership of IPLE is international and includes chartered
engineers,
scientists and physicists representing the various lighting
interests of local
authorities, manufacturers and national
associations.

1.3
The
opinions and recommendations expressed hereafter represent the views
of an
Institution solely and totally committed to the provision and
improvement of
lighting in the external environment as a service amenity
giving assurance and
safety to members of the public during the hours of
darkness.

1.4
The
technical expertise developed by the multi-disciplined Engineers
within the
Institution includes full knowledge of the production and
distribution of light
to reveal the presence and movement of objects to
all road users and thereby to
promote night-time safety.

2.
PRINCIPLES
OF ROAD AND VEHICLE LIGHTING

2.1
Road
Lighting

Perception
of a visual scene depends upon contrasts of light and shade or
of colour. At
road lighting levels, colour contrasts are rarely
perceptible, so it is
necessary to rely upon luminance (brightness)
contrast.

2.2
Luminance
contrast may be positive or negative i.e. an object, or part of
an object, may
appear brighter or darker than its immediate background.
Against bright road
surfaces or surroundings, objects are in general,
revealed by negative
contrast, or silhouette.

2.3
The
object of fixed road lighting is, therefore, to provide a uniformly
bright
carriageway and to direct adequate light to the immediate
surroundings, either
to produce a bright background or, if this is absent,
to reveal objects by
positive contrast.

2.4
Glare

Particular
care is also taken to restrict glare by severe limitation of
light intensities
emitted from the fixed lanterns in directions
approaching the horizontal.

2.5
DisabilityGlare

Disability
Glare is a physical factor caused by the light entering the eye
directly from
sources within the field of view, creating a Veiling
Luminance over the retina,
which reduces the perception of any luminance
contrast between an object and
its background. A simple experiment will
demonstrate that this Veiling Luminance
is practically instantaneous in
its effect and is a physical reality from which
no one is
immune.

2.6
Headlights

On
an unlit road a driver has to use headlights whereby objects are seen
mainly by
positive contrast.

2.7
Dipped
Headlights

If
dipped headlights are correctly adjusted, they are adequate for driving
at
reasonably high speeds on unlit roads by similar dipped headlights on
opposing
vehicles.

2.8
On
well lit roads, drivers know from experience that switching on their
own dipped
headlights rarely assists them in seeing objects ahead. The
reason for this is
that the fixed road lighting reveals objects primarily
by negative contrast,
which is counteracted by dipped headlights which
promote positive contrast.
This inevitably means that disability glare
from opposing dipped headlights is
very much more severe than on unlit
roads when all vehicles use dipped
headlights.

2.9
An
appropriate reduction in the power of dipped headlights to overcome
this
disadvantage, would of course, render them inadequate for high speed
driving on
unlit roads.

2.10
For
this reason the Secretary of State for Transport, proposes to make
Regulations
requiring motor vehicles to be fitted with DIM-DIP LIGHTING
DEVICE, which can
be manually operated by the driver and this proposal is
strongly supported by
the Institution.

2.11
This
device would automatically switch on the headlights with DIM-DIP
BEAMS when the
sidelights are switched on whilst the engine is running.
This would make it
impossible to drive using only side-lights and drivers
would be free to use
DIM-DIP or DIPPED HEADLIGHTS on any road, regardless
of the quality of the
final road lighting.

2.12
Drivers
would appreciate the good sense of having this discretion
available to them and
would act appropriately, just as they use FULL or
DIPPED HEADLIGHTS, on unlit
roads. There would also be no objections to
making legislation enforcing the
use of at least DIPPED or DIM-DIP LIGHTS
at all times during the hours of
darkness.

3.
PREVIOUS
EXPERIMENTS ON DIPPED HEADLIGHTS

3.1
In
1963 a dipped headlight campaign was launched for a limited period
in
Birmingham and this repeated in the following year in Birmingham and
four other
large towns.

3.2
The
accident records recorded for those towns operating dipped
headlights
campaigns, were compared with six similarly sized towns not
holding similar
campaigns. The analysis of the data obtained led to the
conclusion that,
"the usage of dipped headlights had a negligible
effect on total
causalities during the dark hours", and in campaign
towns, other than
Birmingham, "there was some evidence of an adverse
effect on total
casualties during the hours of
darkness".

3.3
The
overall conclusion relating to dipped headlight usage was "the
only
significant change found which can be associated with the use of
dipped
headlights at night, was the reduction of pedestrian accidents on
less well-lit
roads, but dipped headlights have no benefit and may even be
harmful on
well-lit roads". (Refer RRL Report LR 210-1968,
"Some Further Data
relating to the Dipped Headlights Campaign in
Birmingham and other
towns").

3.4
The
provision of DIM-DIP LIGHTING DEVICES is estimated to be below
£4.

3.5
The
Institution is convened to see in the popular press that there is
opposition to
the DIM-DIP proposals from areas of vested interest because
they consider the
proposal to be a barrier to trade.

3.6
It
is the strongly held view of the Institution as a professional body
responsible
for the improvement of the science of lighting on roads, that
the use of
vehicle DIPPED HEADLIGHTS on well lit roads is not appropriate
because of
discomfort glare and dazzle which reduces the effectiveness of
vision to the
danger of the pedestrian and the driver.

3.7
In
the absence of a better system it is understandable that the drivers
have
adopted the wide use of the DIPPED BEAM in well lit streets to try to
improve
pedestrian and vehicle conspicuity.

3.8
It
is important to note that France, on the 15th October 1979, made the
use of
dipped headlights in built-up areas compulsory. However, as the
compulsory use
of dipped headlights HAD NOT RESULTED IN ANY SIGNIFICANT
CHANGES and, following
protests from motorists and road users in general,
on the 19th December 1981,
the Interdepartmental Committee on Road Safety,
comprising of the Home
Secretary, the Minister of Transport and the Deputy
to the Minister for Leisure
Activities and chaired by the Prime Minister,
REVOKED THE COMPULSORY USE OF
DIPPED HEADLIGHTS IN BUILT-UP AREAS IN
FRANCE.

3.9
The
French Medical Automobile Association had conducted a survey of
dipped
headlight usage and found that out of 204 responses by doctors, 56
per cent
opposed the use of dipped headlights on lighted roads caused
medical effects
which were contrary to road safety.

3.10
The
responses against the use of dipped headlights included four
from
Ophthalmologists, including a Professor of the Paris Faculty of
Medicine, and
the President of Practising Opthalmologists. Some 81 per
cent of the French
medical profession were against the compulsory use of
dipped headlights in
built-up areas.

4.
PUBLIC
LIGHTING AND ROAD SAFETY

4.1
In
this country the number of night-time accidents (including nonfatal
accidents)
for related travelling distances, is approximately 1.8 times
that by daytime.
Studies in many countries carried out by various
institutions, have shown
conclusively that good road lighting can help to
reduce the number of
night-time accident by more than 30%. The majority
of these studies relate to
night-time accidents before and after the
provision of upgrading of lighting is
made.

4.2
There
is simple evidence to indicate that improved lighting of roads leads
to an
appreciable reduction in accidents at night. Studies show
reductions of 30 to
45 per cent for urban roads, 19 to 48 per cent for
rural roads, and 16 to 55
per cent for motorways. Additionally, the
proportion of fatal and serious
accident occurring at night, is
reduced.

4.3
Investigations
on the use of sidelights and dipped headlights in built-up
areas, were the
subject of a Report issued in 1969 by the Institute for
Road Safety Research,
SWOV, The Netherlands. The Report concluded that
the glare caused by
approaching cars headlights with European dipped
headlight or E beam, is
unacceptably serious on well-lit roads, especially
if there are a large number
of approaching vehicles, and sidelights hardly
ever cause glare but in many
cases are not conspicuous enough. The Report
recommended that is was advisable
to seek a lighting system for the front
of vehicles with a light intensity
between the present dipped headlights
and sidelights, and guaranteeing adequate
conspicuousness.

4.4
A
similar study was carried out by A J Fisher while at the Department
of
Transportation and Environmental Planning, University of Birmingham,
the work
being supported by the Science Research Council. The road
research group S2 of
the Organisation for Economic Co-operation and
Development (OCED) had
identified the question of the use of headlights in
street lighting as one
requiring research and international
co-operation.

4.5
Previous
studies by the Roads Research Laboratory and the Institute for
Road Safety
Research (SWOV) indicted that it was undesirable to require
that dipped
headlights be used at all times in order to secure their use
on unlit or poorly
lit streets, while accepting that present sidelights
were adequate.

4.6
A
series of tests were carried out to establish the luminous requirements
of a
vehicle front light that is adequately conspicuous without being
glaring. The
report published in 1974 recommended that the optimum
lighting from vehicle
front lights should be a town beam based on dimming
the present dipped
headlights to an intensity straight ahead of 80-
candelas.

4.7
The
Joint Committee of CIE (International Commission on Illumination)
issued the
following statement in 1975 recognising the problem and the
research work
carried out. "It is recommended that a town beam be
introduced which is
intermediate in intensity between the currently used
low beam and sidelights.
Such a beam should have a luminous intensity
between 50 and 100 candelas and
have an area similar to that of the
current headlights".

4.8
The
Road Research Laboratory had presented Report LR66 in 1967 which
included
reference to the examination and possible introduction of dimmed
headlight
systems with details of the London postal region headlight
experiment on G.P.O.
vehicles. This report concluded that the system was
reliable and could have
possibly contributed to a reduction in night-time
accidents.

4.9
The
Transport and Research Laboratory conducted further study on the use
of
automatic headlight dimming systems and further to trials on Police and
G.P.O.
vehicles, a Report 880 was issued in 1979 entitled "Town Beams
for
Vehicles - Experience with an Automatic Headlight Dimming
System". The
Report concluded that the automatic system was
unacceptable and future work
should be directed towards a safety
assessment of the manual system.

5.
RECOMMENDATIONS

5.1
In
conclusion, the IPLE in considering the foregoing submission, in
cognisance of
matters relating to the external night-time environment, the
relevance to light
and the physiological responses of the human eye, the
cost-effectiveness of
fixed road lighting systems, the need to ensure the
safety of all road users,
the inadequacy of sidelights for vehicles in
motion and the overall need to
present a situation in which reasonable
legal enforcement can be made, make the
following recommendations to the
Transport Committee for consideration.

5.2
Road
Lighting

5.2.1
To
provide encouragement to Local Authorities to the installation or
upgrading of
road lighting on all urban roads to conform with the British
Standards
Institution Code of Practice for Road Lighting, CP 5489: 1974 or
subsequent
revision thereof.

5.2.2
To
consider financial assistance to Local Authorities to upgrade and
modernise
road lighting installations to improve efficiency and reduce
maintenance costs.

5.3
Vehicle
Lights

5.3.1
To
enforce the mandatory fitting of Dim-Dip lighting of the recommended
type to
all new vehicles at an appropriate date.

5.3.2
To
promote the development of devices incorporating economic electric
circuitry
similar to that proposed by the Secretary of State for
Transport, of existing
vehicles to be converted to the recommended
dim-dipped type.

5.3.3
To
encourage Industry to carry out research into improved vehicle
lighting
systems.

5.3.4
To
encourage the use of dim-dipped headlights on well lit
roads.

5.3.5
To
seek improved legislation to ensure correct setting of vehicle lights
in the
M.O.T. tests and that random roadside checks are carried
out.